Kidney transplantation across minor ABO incompatibility the use of A2 to B transplantsGilbert, Alexander J.Current Opinion in Organ Transplantation: August 2019 - Volume 24 - Issue 4 - p 365–369 doi: 10.1097/MOT.0000000000000672 KIDNEY PANCREAS: Edited by Matthew Cooper Buy Abstract Author InformationAuthors Article MetricsMetrics Purpose of review On 4 December 2014, the new kidney allocation system (KAS) went into effect. As part of this system, UNOS approved for the first time a national system with a specific mechanism affording priority to allocate kidneys across so-called ‘minor ABO incompatibility’ from blood group A2 donors into blood group B recipients. This significantly increased the number of such transplants done and the opportunities to learn about the specifics of such transplants. Recent findings A2 to B transplants have been demonstrated to be well tolerated, effective, and cost-effective ways of addressing disparities in the allocation system. Further data about the use of anti-A titers and the limits to successful transplant have better defined the bounds of who can benefit from such transplants. Summary The success thus far with A2 to B transplants should increase comfort and acceptance of the allocation policy changes and we should see further increases in centers willing to use such transplants to better address inequalities in the system. Medstar Georgetown Transplant Institute, Medstar Georgetown University Hospital, Washington DC, USA Correspondence to Alexander J. Gilbert, MD, 3800 Reservoir Road, NW, PHC Building, 2nd Floor, Washington DC 20007, USA. Tel: +1 202 444 0621; e-mail: Alexander.J.Gilbert@gunet.georgetown.edu Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.